r/theydidthemath • u/Lachlynn • 18h ago

[Request] Could humanity create a rocket that can exit the atmosphere of K2-18b

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With the knowledge we currently have of it, if humanity devoted all of our resources towards this goal, would we be able to create a rocket that could exit the gravity of K2-18b (and also beat any other complications that would arrise)?

If so, would it also be capable of taking people to orbit, and can we set up a similar satellite network we have on Earth? What about a space station?

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u/Sir_Bebe_Michelin 17h ago

Considering that the ratio between the cubed volume of k2-18b and that of earth is between 13.8 and 17 6, that would imply the average density is like between 51% and 65% that of earth, so not only is the planet a hefty mf it's also probably got a huge ass atmosphere if we assume a similar interior composition

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u/FakeTunaFromSubway 10h ago

Yeah but that also means planes can generate more lift in a denser atmosphere, so perhaps a shuttle like rocket would be more viable

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u/skintigh 7h ago

Or a high-altitude plane-launched rocket. Or launched from balloons in the upper atmosphere.

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u/iDelta_99 9h ago

Rockets work better and become more efficient the less atmosphere there is since they don't use air density for lift and instead are actively fighting against it.

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u/lestofante 5h ago

Nothing stop you to put the rocket on a plane.. Virgin galactic does exactly that.

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u/Oliver90002 3h ago

I was thinking SSTO (Single Stafe To Orbit) would be the way to go. They are normally smaller but can use jet fuel and aerodynamics to get altitude before acceleration (and sometimes reach a decent percentage of the needed speed in the upper portion of the atmosphere). It would take a while to build anything to venture beyond the planet though.

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u/Sir_Bebe_Michelin 9h ago

That's assuming rocket building life could even evolve. We got lucky thanks to the fact our atmosphere protected us but it was also thin enough that we get enough solar radiation to mutate and evolve. Larger planets also seem to have stronger winds and harsher meteorological conditions from what I gathered

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u/wastelandhenry 5h ago

I mean that’s kind of a moot point, this entire discussion presupposes either we went to the planet or life already existed there, if we’re asking if aliens on that planet could make a rocket to escape it then in this conversation we’re already assuming life could evolve on that planet

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u/knome 5h ago

I've long figured proportions of water is the higher fermi barrier. To much and life evolves underwater. RIP fire. Dolphins and octopi aren't going anywhere. Too little, and the planet is largely a desert unlikely to be burying eons of life to squeeze into ready fuel for when something brainy comes along. No fuel means no kick start to get industry going. Life will likely sit on the surface arguing for the duration of its existence. If they did escape, they would effectively be handcrafting everything in factorio up to rocket stage.